Refactor isProperFraction function logic and add tests for edge cases with mixed signs

Author: mervereis

Sprint-3/1-implement-and-rewrite-tests/implement/2-is-proper-fraction.js

@@ -11,7 +11,7 @@
 // execute the code to ensure all tests pass.
 
 function isProperFraction(numerator, denominator) {
-  return numerator > 0 && denominator > 0 && numerator < denominator;
+  return Math.abs(numerator) < Math.abs(denominator);
 }
 
 // The line below allows us to load the isProperFraction function into tests in other files.

Sprint-3/1-implement-and-rewrite-tests/rewrite-tests-with-jest/2-is-proper-fraction.test.js

@@ -32,3 +32,9 @@ test(`should evaluate correctly with various negative number combinations`, () =
   expect(isProperFraction(-5, 2)).toEqual(false);
   expect(isProperFraction(5, -2)).toEqual(false);
 });
+
+test(`should handle edge cases with mixed signs correctly`, () => {
+  expect(isProperFraction(4, -7)).toEqual(true);
+  expect(isProperFraction(-4, -7)).toEqual(true);
+  expect(isProperFraction(-4, 7)).toEqual(true);
+});